Key components include neuromodulators binding to GPCRs, glutamate release and NMDAR activation, retrograde messengers, gliotransmitters, and intracellular signaling cascades involving PLC, IP3, and calcium-induced calcium release (CICR). The illustration integrates structural elements—vesicles, receptors, ion channels, and endoplasmic reticulum—into a clear, color-coded schematic that emphasizes functional relationships within the synapse.